Initiates a stream or datagram connection to the destination specified
by remote_socket. The type of socket created
is determined by the transport specified using standard URL formatting:
transport://target. For Internet Domain sockets
(AF_INET) such as TCP and UDP, the target portion
of the remote_socket parameter should consist of
a hostname or IP address followed by a colon and a port number. For Unix
domain sockets, the target portion should point
to the socket file on the filesystem.

Note:

The stream will by default be opened in blocking mode. You can
switch it to non-blocking mode by using
stream_set_blocking().

Parameters

remote_socket

Address to the socket to connect to.

errno

Will be set to the system level error number if connection fails.

errstr

Will be set to the system level error message if the connection fails.

timeout

Number of seconds until the connect() system call
should timeout.

Note:
This parameter only applies when not making asynchronous
connection attempts.

Note:

To set a timeout for reading/writing data over the socket, use the
stream_set_timeout(), as the
timeout only applies while making connecting
the socket.

flags

Bitmask field which may be set to any combination of connection flags.
Currently the select of connection flags is limited to
STREAM_CLIENT_CONNECT (default),
STREAM_CLIENT_ASYNC_CONNECT and
STREAM_CLIENT_PERSISTENT.

Return Values

Errors/Exceptions

On failure the errno and
errstr arguments will be populated with the actual
system level error that occurred in the system-level
connect() call. If the value returned in
errno is 0 and the
function returned FALSE, it is an indication that the error
occurred before the connect() call. This is
most likely due to a problem initializing the socket. Note that
the errno and
errstr arguments will always be passed by
reference.

Notes

Warning

UDP sockets will sometimes appear to have opened without an error,
even if the remote host is unreachable. The error will only
become apparent when you read or write data to/from the socket.
The reason for this is because UDP is a "connectionless" protocol,
which means that the operating system does not try to establish
a link for the socket until it actually needs to send or receive data.

Note: When specifying a numerical IPv6 address
(e.g. fe80::1), you must enclose the IP in square
brackets—for example, tcp://[fe80::1]:80.

The remote_socket argument, in its end (well... after the port), can also contain a "/" followed by a unique identifier. This is especially useful if you want to create multiple persistent connections to the same transport://host:port combo.

# Some may find it useful to know that your caCert # must be in pem format, and that PHP seems to like # your key, cert, and cacert pem's to be concatenated# in a single file (I suffered various "unknown chain" # errors, otherwise)## So, (linux users), concat your components as follows:# (where current working dir is dir where # cert components are stored)## cat key.pem >certchain.pem# cat cert.pem >>certchain.pem# cat cacert.pem >>certchain.pem## Then, the php....##################################

stream_socket_client is much easier and faster to use to direct sockets, because you can use directly fwrite / fget / fclose functions, but I find hard to find how to connect to a UNIX domain socket. The URL to use is "udg:///path/to/socket".

I came here since fsockopen() does not support any SSL certificate checking in PHP5.

while curl is nice, I use stream_socket_client() to make XML-RPC POST requests via HTTPS and since I have not found any PHP code around that does this, I'll attach an example that also includes HTTP-Digest Auth (eg. trac's WikiRPCInterface2):